Horizontal directional drilling system including sonde position detection using global positioning systems

ABSTRACT

A locator device and methods of use are disclosed. The locator device includes a first locating system configured to generate to sense an electromagnetic field emanating from a sonde associated with a drill head, and a second locating system including a global positioning system. The locator device includes a display on the locating system configured to display a map of the area in which the locator device resides based on a location detected by the global positioning system. The locator device also includes control electronics configured to, upon receipt of an input from a user, record location data in a memory associated with the locator device for use by a horizontal directional drilling control system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/127,839, filed Aug. 5, 2014, which is a National Stage Application ofPCT/US2012/043589, filed Jun. 21, 2012, which claims priority to U.S.Provisional Patent Application No. 61/499,581, filed Jun. 21, 2011, U.S.Provisional Patent Application No. 61/530,155, filed Sep. 1, 2011, andU.S. Provisional Patent Application No. 61/625,190, filed Apr. 17, 2012,the disclosures of which are hereby incorporated by reference in theirentireties. To the extent appropriate, a claim of priority is made toeach of the above disclosed applications.

TECHNICAL FIELD

The present disclosure relates generally to detection of undergroundobjects, such as a sonde. In particular, the present disclosure relatesto systems and techniques using global positioning systems for detectinga position of a sonde.

BACKGROUND

Utility lines for water, electricity, gas, telephone, and cabletelevision are often run underground for reasons of safety andaesthetics. Sometimes, the underground utilities can be buried in atrench that is subsequently back filled. However, trenching can be timeconsuming and can cause substantial damage to existing structures orroadways. Consequently, alternative techniques such as horizontaldirectional drilling (HDD) are becoming increasingly more popular.

A typical horizontal directional drilling machine includes a frame onwhich is mounted a drive mechanism that can be slidably moved along thelongitudinal axis of the frame. The drive mechanism is adapted to rotatea drill string about its longitudinal axis. The drill string comprises aseries of drill pipes threaded together. Sliding movement of the drivemechanism along the frame, in concert with the rotation of the drillstring, causes the drill string to be longitudinally advanced into orwithdrawn from the ground.

In a typical horizontal directional drilling sequence, the horizontaldirectional drilling machine drills a hole into the ground at an obliqueangle with respect to the ground surface. To remove cuttings and dirtduring drilling, drilling fluid can be pumped by a pump system throughthe drill string, over a drill head (e.g., a cutting or boring tool) atthe end of the drill string, and back up through the hole. After thedrill head reaches a desired depth, the drill head is then directedalong a substantially horizontal path to create a horizontal hole. Oncethe desired length of hole has been drilled, the drill head is thendirected upwards to break through the ground surface, completing a pilotbore.

When horizontal directional drilling is performed, it is important toknow the location and direction of travel of underground drillingequipment, to ensure that the underground line is routed properly, andto the correct destination. There are various ways to locate undergroundutilities and underground drill heads, for example, usingelectromagnetic (EM) locators. EM locators typically include a receiverand a transmitter, which may be a radiating underground conductor. Insome systems, a radiating underground conductor can be a sonde, abattery operated cylindrical device having a length of a few centimetersto few decimeters. A typical sonde has a single coil oriented along thecylindrical axis (also known as the dipole axis), with an integratedtone transmitter that causes an induced EM field to emanatesymmetrically from the sonde. An above ground EM locating receiverdetects and processes the signal, and presents transmitter locationinformation to a user. In this manner, an underground conduit pipe canbe traced above ground as a sonde is pulled or pushed through from oneend, or a trenchless underground boring tool can be guided frominformation derived from the position of the sonde. Conventional EMlocators, however, do not provide for precise determination of thelocation and orientation of sondes and exhibit some practical uselimitations relating to the geometric relationship between the EMlocator receiver and the sonde transmitter.

Attempts to improve location techniques typically revolve around takingadditional EM field measurements from known locations. For example, asdescribed in U.S. Patent Application No. 2010/0141261, a location systemincludes a sonde configured to distribute radio frequency signals alongthree axes, to communicate with an above-ground radio frequency locator.The location system detects the sonde location by measuringelectromagnetic field and phase values at above ground locationstraversing across a path of travel of the sonde.

However, such advanced field measurements require a great deal ofcalibration to accurately detect the presence of the sonde, therebytaking additional time to measure for and locate the sonde. Thisinvolves a number of operations at the job site prior to drilling to setup the area to execute a planned drilling operation along a desiredroute. Furthermore, even once such measurements are taken, the positionof the sonde and associated drill head must be extrapolated relative toknown points and mapped relative to those points, which adds tocomputational complexity. Additionally, even once such locations are infact determined, it can be difficult to assess, both at the drilling rigand remotely (e.g., by a project manager of a construction company,utility or other entity executing or requesting the boring operation).

For these and other reasons, improvements are desirable.

SUMMARY

In accordance with the following disclosure, the above and other issuesare addressed by the following:

In a first aspect, a locator device is disclosed. The locator deviceincludes a first locating system configured to generate to sense anelectromagnetic field emanating from a sonde associated with a drillhead, and a second locating system including a global positioningsystem. The locator device includes a display on the locating systemconfigured to display a map of the area in which the locator deviceresides based on a location detected by the global positioning system.The locator device also includes control electronics configured to, uponreceipt of an input from a user, record location data in a memoryassociated with the locator device for use by a horizontal directionaldrilling control system.

In a second aspect, a method of locating a sonde associated with anunderground drill head is disclosed. The method includes calculating anapproximate location of a sonde based on a direction and distance from adrilling rig, and placing a locator device at the approximate locationusing a global positioning system. The method further includesdetermining a signal strength of an electromagnetic signal generated bythe sonde when the locator device is at the approximate location. Themethod also includes determining a location of the sonde by placing thelocator device at a position near the approximate location, the positioncorresponding to a maximum electromagnetic signal strength.

In a third aspect, a method of operating a horizontal directionaldrilling machine is disclosed. The method includes placing a locatordevice at a plurality of positions along a planned bore path, and atleast of the plurality of positions, capturing a location of the locatordevice using a global positioning system, thereby capturing a routedefined by a plurality of captured locations. The method furtherincludes downloading the route to a horizontal directional drillingcontrol system.

In a fourth aspect, a GPS-based locator device useable in horizontaldirectional drilling applications is disclosed that includes a locatingsystem including a global positioning system and a display configured todisplay a map of the area in which the locator device resides based on alocation detected by the global positioning system. The GPS-basedlocator device includes control electronics configured to, upon receiptof an input from a user, record location data in a memory associatedwith the locator device for use by a horizontal directional drillingcontrol system, and a communication interface configured to communicatethe location data to a horizontal directional drilling control system.

In a further aspect, a horizontal directional drilling system isdisclosed that includes a horizontal directional drilling machinepositioned at a job site, and a horizontal directional drilling dataserver positioned remotely from and communicatively connected to thehorizontal directional drilling machine. The horizontal directionaldrilling data server includes a database configured to collectoperational data from the horizontal directional drilling machine in atleast near real-time, the operational data including GPS data indicatingan approximate location of the horizontal directional drilling machine.

In a still further aspect, a horizontal directional drilling system isdisclosed that includes a horizontal directional drilling machinelocated at a job site and including a drill string, a drill head coupledto the drill string, a control system, and a communication interfacecapable of communicating with a remote computing system. The horizontaldirectional drilling system also includes a mobile locator deviceincluding a sensing device configured to measure attributes of the drillhead to generate the drill head attribute data, and a GPS receiverconfigured to receive GPS data indicating an approximate location of themobile locator device. The mobile locator device also includes a radioconfigured to broadcast position data and drill head attribute data tothe horizontal directional drilling machine. The horizontal directionaldrilling system also includes a horizontal directional drilling dataserver positioned remotely from the job site and configured to receivethe GPS data from the horizontal directional drilling machine via thecommunication interface.

In a further aspect, a horizontal directional drilling data server isdisclosed that is communicatively connected to a plurality of horizontaldirectional drilling machines at geographically dispersed locations. Thehorizontal directional drilling data server includes a databaseconfigured to store a plurality of types of data from each of thehorizontal directional drilling machines selected from the groupconsisting of: bore plan data; boring logs; job data; site data; rigtelematics data; maintenance data; and reports.

In a still further aspect, a method of determining a position of a borepath having a starting location, a first location, and a second locationis disclosed. The method includes boring from the starting location tothe first location, estimating a region in which the first locationresides based at least in part on GPS data captured by an above-groundlocator, and narrowing the region based on a length of a drill stringextending from the starting location to the first location. The methodfurther includes boring from the first location to the second location,estimating a second region in which the second location resides based atleast in part on GPS data captured by an above-ground locator, andnarrowing the second region based on a second length of a drill stringextending from the starting location to the second location. The methodalso includes narrowing the first region based on the narrowed secondregion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic diagram of an overall arrangement in whichhorizontal directional drilling operations are coordinated and tracked,according to a possible embodiment of the present disclosure;

FIG. 1B is a schematic diagram of a horizontal directional drillingsystem, according to a possible embodiment of the present disclosure;

FIG. 2A is a schematic diagram of a horizontal directional drillingsystem including a locator device integrating GPS features, according toa possible embodiment of the present disclosure;

FIG. 2B is a schematic diagram of a horizontal directional drillingsystem including a locator device and a GPS locator, according to analternative embodiment of the present disclosure;

FIG. 3 is a flowchart of a method of locating a sonde associated withunderground drilling equipment, according to a possible embodiment ofthe present disclosure;

FIG. 4 is a flowchart of a method of operating a horizontal directionaldrilling system, according to a possible embodiment of the presentdisclosure;

FIG. 5 is a schematic of an example display illustrating a mapped routefor a horizontal directional drilling process, according to a possibleembodiment of the present disclosure;

FIG. 6 is a schematic of an example display illustrating a currentlocation of a sonde superimposed on a mapped route during a horizontaldirectional drilling process, according to a possible embodiment of thepresent disclosure;

FIG. 7 illustrates an example drilling system in an example globalpositioning system environment;

FIG. 8 is a block diagram of an HDD system including an HDD machine andan example locator;

FIG. 9 is a block diagram of a computer system forming part of anexample receiver network;

FIG. 10 is a flowchart of a method of locating underground drillingequipment using a differential GPS analysis, according to a possibleembodiment of the present disclosure;

FIG. 11 is a flowchart of a method of locating underground drillingequipment using a differential GPS analysis, according to a possibleembodiment of the present disclosure;

FIGS. 12-14 are flowcharts providing methods that can be used inlocating underground drilling equipment using carrier phase tracking;

FIG. 15 is a flowchart illustrating a triple difference method that issuitable for use in implementing each of steps of the method of FIG. 14;

FIG. 16 is a flowchart illustrating a method by which a GPS system canbe used to guide (i.e., direct) an operator to the approximate locationof the drill head;

FIG. 17 is a schematic illustration of GPS-based locating techniqueuseable in connection with the methods and systems disclosed herein;

FIG. 18 is a flowchart illustrating a method by which location of adrill head can be refined, using a GPS-based locator system as discussedherein;

FIG. 19 is a schematic diagram of a horizontal directional drillingmanagement system, according to an example embodiment; and

FIG. 20 is a flowchart illustrating a method by which a horizontaldirectional drilling operation can be performed.

DETAILED DESCRIPTION

In general, the present disclosure relates to an overall arrangement inwhich horizontal directional drilling operations are coordinated andtracked, and in particular methods by which locations, status, andperformance of horizontal directional drilling equipment can be trackedand assessed.

In some aspects, the present disclosure relates to a locating device fora horizontal directional drilling (HDD) system, in which a globalpositioning system (GPS) can be integrated, thereby allowing a user topreplan and map a path of travel of a drill head and associated sonde.According to the various embodiments disclosed herein, a number ofadvantages are provided by use of GPS, including simplifyinglocation-based calculations, while providing additional flexibilityregarding mapping and planning of routes for underground HDD procedures.

Referring now to FIG. 1A, an overall arrangement 10 useable forcoordinating and tracking horizontal directional drilling operations isdisclosed. The arrangement 10 generally allows for planning,supervision, management, and review of horizontal directional drillingoperations at one or more job sites without requiring that allindividuals be present at that job site. In particular, the arrangement10 allows for distributed, real-time or near real-time job datacommunication across a distributed network, for example to allow remotemonitoring.

In the embodiment shown, the arrangement 10 includes a plurality of jobsites 12, shown as job sites 12a-b. Each of the job sites 12 aregenerally locations at which horizontal directional drilling operationsare requested and performed. In embodiments, the various job sites 12can be at geographically dispersed locations, and generally only requiresome type of accessible communicative connection (e.g., via an Internet,cellular, satellite, or other data connection) capable of maintainingreal-time or near real-time data exchange with remote systems.

In the embodiment shown, each of the job sites has at least onehorizontal directional drilling (HDD) machine 14 positioned at thatsite, and including an antenna or other type of data transmissionmechanism. In the embodiment shown, a wireless data communicationmechanism is disclosed. However, in various embodiments, wired and/orwireless data communications of various types could be used.

In the embodiment, each of the job sites are communicatively connectedto a data repository, illustrated as a HDD data server 16, via a network18.

The HDD data server 14 generally is configured to store variousinformation relevant to one or more drilling operations, including boreplans or other pre-drilling operational parameters, as well as dataregarding operational parameters of the HDD machine, details regardingplanned, current, and past locations of a drill string (as discussedbelow), or other location information could be stored at the HDD dataserver 16 as well (e.g., map data, topographic data). Other information,such as maintenance information regarding the HDD machine 14, can bereceived from the HDD machines 14 at job sites 12 as well. The network18 represents any of a variety of communicative connections, asdescribed above, typically including one or more wireless dataconnections, such as cellular, satellite, or wireless Internet (e.g.802.x) data communication.

A remote computing system 20 can be used to access data at the HDD dataserver 16, for example to monitor and/or affect operation of one or moreof the HDD machines 14 at job sites 12. For example, a user of theremote computing system 20 can define one or more bore plans for use ata job site, or access and modify such bore plans prior to or during aHDD job. Additionally, due to relatively constant data communicationbetween a HDD machine 14 and the HDD data server 16, a user of theremote computing system 20 can monitor operation of the HDD machine 14during the boring operation, despite being located remotely from the jobsite 12, in real-time or near real-time.

In some embodiments, the HDD data server 16 and associated job sites 12are affiliated with a common owner or controller, such as a singleconstruction company or utility. As such, individuals affiliated withthat entity are provided access to data relating to the one or more jobsites associated with the entity, both current and historical. Asexplained in further detail below, this allows remote users (i.e., usersnot physically located at a particular job site) to track progress ofHDD operations, and to assess performance and accuracy of HDD proceduresbased on planned and actual boring processes.

An example horizontal directional drilling arrangement 100 at aparticular job site, also referred to herein as a reference site, isdisclosed in FIG. 1B. The arrangement 100 includes a horizontaldirectional drilling (HDD) machine 102 and a locator device 104. The HDDmachine 102, also referred to herein as a drilling rig, is configured todrive and control a drill string 103 having a drill head 106 at a farend. The drill head 106 has an associated sonde 108 configured forone-way or two-way communication with surface electronics, including acontrol system for the HDD machine 102 (disclosed in FIG. 2, below) andthe locator device 104.

As further discussed below, the locator device 104 can be any of anumber of different types of location systems, and typically in theembodiments disclosed herein incorporates a locator circuit including aglobal positioning system (GPS). An operator 110 can move the locatordevice 104 above ground, allowing the locator device to communicate withthe sonde 108, thereby tracking the location of the sonde and associateddrill head 106. This information can be communicated with the HDDmachine 102 via a communication interface, as discussed below inconnection with FIG. 2. Optionally, rather than being used by anoperator 110, the locator device 104 can be either an automated machineor a self-propelled device such as a robot.

In general, during operation of the HDD machine 102, a drill string 103extends from the HDD machine 102 via an underground path. The HDDmachine 102 steers the drill string 103 by communicating particularcommands to the drill head 106, thereby forming a path of a desiredshape and at a desired depth. The locator device 104 can be used totrack the position of the drill head 106, to allow the operator 110 tocommunicate course corrections back to the HDD machine 102, to arrive ata desired destination while avoiding obstacles as necessary (e.g., rocks112 as shown, but also including buildings, other undergroundinstallations or wires, pipes, etc.).

Referring now to FIG. 2A, an example schematic diagram of a HDD system200 including the HDD machine 102 and the locator device 104 is shown.In the embodiment shown, the HDD machine 102 includes a control system202 configured to direct operation of the drill string 103 via amechanical drive unit 204. The HDD machine 102 also includes a display206 and I/O interface 208, which allow an operator to view a currentoperational status, planned route (i.e., bore plan), and various otherparameters of the HDD machine 102. The HDD machine 102 also includes acommunication interface 210 configured for two-way communication withthe locator device 104. The communication interface 210 can use, invarious embodiments, any of a number of types of wired or wirelesscommunication connections; in certain embodiments, the communicationinterface 210 uses a persistent wireless connection to the locatordevice, such that data associated with a location of the sonde 108 canbe communicated back to the HDD machine 102.

The locator device 104 includes a control circuit 220 and a plurality oflocator circuits, shown as GPS locator circuit 222 and EM locatorcircuit 224. The control circuit 220 performs a number of operationsrelating to (1) developing a bore plan for a drill rig, and (2) trackinga drill head and associated sonde during operation of the drill rig. Thecontrol circuit receives information from the GPS locator circuit 222 todetermine a current location of the locator device 104, and uses the EPlocator circuit 224 to receive communications from the sonde 108 (e.g.,to associate the current location of the locator device with thelocation of the sonde). An antenna 226 associated with the EM locatorcircuit is configured to pick up electromagnetic signals from the sondefor processing at the EM locator circuit. The EM locator circuit 224also optionally receives information regarding other operationalparameters of the sonde 108 and associated drill head 106, for examplerotational or linear speed, temperature, or other current operatingparameters, such as a pitch of bit, clock/roll position of bit, depth ofbit, fluid pressure at bit, product tension measured at bit, andvibration at the bit. Other parameters can be tracked as well.

The antenna 226 can be, for example a simple antennae device formeasuring a magnetic field information of the signal being transmittedby the sonde 108, as would be necessary to generate signal strengthinformation, or alternately the antenna 226 could be more elaborate toalso measure additional characteristics of the magnetic field—as wouldbe required to also measure the shape/orientation of the “flux lines”associated with the sonde 108. For example, details pertaining to athree-axis antenna may be found in U.S. Pat. No. 6,768,307, filed Mar.21, 2003, and titled “Flux Plane Locating in an Underground DrillingSystem” and in U.S. Pat. No. 7,304,479, filed Jan. 4, 2007, and titled“Flux Plane Locating in an Underground Drilling System,” the disclosuresof which are hereby incorporated herein by reference.

The locator device 104 also includes a complementary communicationinterface 228 that communicates with the communication interface 210 ofthe HDD machine 102. The locator device 104 therefore can transmit boreplan information, current operational status information, or other typesof information to the HDD machine, such that each machine can track andcontrol operational features of the drill head 106.

The locator device 104, in certain embodiments, enables display of anumber of parameters relating to operation of the drill head 106 on adisplay 230, alongside a map of the current location of the locatordevice 104 and HDD machine 102. The display 230 can be used, forexample, to establish a bore plan, or to track the current position of asonde 108. Associated I/O interfaces 232 allow for a keypad or otherbuttons to be implemented on the locator device 104 as well, for exampleto assist in mapping various features, such as the bore path, boredepth, obstacles, or other information. Example displays are illustratedin FIGS. 5-6, below.

Referring to FIG. 2B, an alternative schematic diagram of a HDD system250 is shown. In this embodiment, the locator device 104 does not have aGPS locator circuit 222 located within that unit. Rather, in thisembodiment, a separate GPS locator device 252 can be used as a “bolt-on”or additive component to the overall system 250, but can be a standalone element. In other words, although in certain embodiments the GPSlocator device 252 can have a housing mountable to an existing locatordevice 104, no modification to an existing locator device may benecessary. As compared to the system 250 above, the separate GPS locatordevice 252 contains the GPS locator circuit 222, as well as a GPScontrol circuit 254, communication interface 256, display 258, and I/Ointerface 260. The GPS locator device 252 generally is configured to bepositioned in proximity with the locator device 104, and can beconfigured to record GPS readings and communicate those readings back tocontrol system 202 of the HDD machine 102 for combination withinformation from the locator device 102 regarding a location of thesonde 108.

In certain alternative embodiments, a data communication connection canbe established between the controllers 220, 254 of the devices 104, 252,such that sonde location and GPS location data can be combined withoutrequiring a communication connection to the HDD machine 102.

FIG. 3 is a flowchart of a method 300 of locating a sonde associatedwith underground drilling equipment, according to a possible embodimentof the present disclosure. The method 300 can be, in variousembodiments, performed using a locator device such as disclosed above,for example during operation of a HDD machine as discussed above. Themethod 300 starts with calculating an approximate location of a drillhead relative to the drill rig, for example by determining the directionand speed of travel from the drill rig of the drill head, or by trackinga number of drill rods included in a particular drill string (step 302).

The method then includes positioning a locator device (e.g., locatordevice 104) at the approximate location (step 304) based on thecalculation in step 302. A signal strength of an electromagnetic signalgenerated by the sonde is then detected at the approximate location(step 306). Additional signal strength readings in the area of theapproximate location can also be taken, such that a location of thesonde can be determined (step 308). This can be performed in a number ofways. For example, repeated measurements in the area of the approximatelocation can be taken until a maximum signal strength is detected, atwhich it can be assumed that the locator device is closest to the sonde(i.e. directly above the sonde and drill head). Alternatively, after anumber of readings, the locator device can perform a triangulationoperation to determine the location of the sonde.

Based on these one or more measurements, a confidence value can bedetermined that relates to the accuracy with which the sonde's positionis known (step 310). This can be based upon, for example, the magnitudeof the sonde readings received at the locator device, the number ofpoints used to triangulate to the sonde, or other factors.

Once the sonde is located, any of a number of operations can beperformed. For example, a user can press a button on the locator device104 to cause its control system to record pitch, depth and GPS locationdata for display at the rig, and to compare to a bore plan being used.The locator device can be configured to generate a map of the area inwhich the locator device is positioned on its display (or alternativelyon the display of the HDD machine), showing the location of the sondeand drill head (step 312). In some such embodiments, the position of thesonde and drill head can be represented by a circle positioned over anarea of a map, the circle representing the confidence value in thelocator device's current computed position for the sonde. An example ofsuch a display is illustrated in FIG. 6, described below.

In addition, the display can include information generated by thelocating device that includes both GPS location information related tothe location of the locating device (e.g., latitude and longitudereadings, or a position relative to a drill rig), and informationrelated to magnetic field strength measurements measured by the locatingdevice, that were emitted by a drill head transmitter. Other informationcould be displayed as well.

Referring now to FIG. 4, a method 400 of operating a horizontaldirectional drilling system is disclosed, according to a possibleembodiment of the present disclosure. The method can be performed by alocator device, an operator, or a combination of the device and othercomponents within an overall HDD system.

In particular, the method 400 can be performed as part of a bore pathplanning process, e.g., as integrated with bore planning software of adrilling rig. The method 400 includes determining an initial location ofa drilling rig in an HDD system, for example using a GPS locator circuitin a locator device (step 402). The method 400 can also includepositioning the locator device at a position along a planned bore path(step 404), and capturing a location of the locator device using the GPSlocator circuit (step 406).

Optionally, the method also includes associating information with eachcaptured point, such as a desired bore depth for the drill string atthat particular point (step 408). Steps 404-408 can be repeated at anumber of points along a planned bore path for a drill string, therebycapturing a route of the drill string. The route captured by the locatordevice can be uploaded to a HDD control system on the drill rig, whichcan translate the mapped route to steering instructions for a drillstring to achieve the desired routing result (step 410). A schematicexample of a mapped route is illustrated in FIG. 5, below.

Additional features for operating the HDD system can be included intothe locator device and drill rig. For example, the mapped route can bedisplayed on one or both of the locator device and the drill rig, eitherbefore, during, or after operation of the drill rig. Either during orafter operation of the drill rig, the locator device or drill rigdisplay can generate an as-built map of the bore path (step 412) basedon captured GPS readings, e.g., when a user presses a button signifyingthat the sonde has been located. Additionally, the display can include acomparison of the mapped route to an actual route travelled by the sondeand drill head, to show deviations (if any) from the mapped route (step414). A schematic example of a comparison between an actual route andmapped route is illustrated in FIG. 6, below. Additionally, when mappingthe route or tracking the sonde, a user of the locator device could alsomanually enter one or more obstacles to be avoided by the drill string,for example a road (e.g., as illustrated in FIGS. 5-6), or otherfeatures, such as rocks, buildings, other underground wires, tunnels, orother installations. These obstacles can be added to a bore planalongside the captured locations and bore depth information, to beuploaded to the drill rig.

FIG. 5 is a schematic of an example display 500 illustrating a mappedroute for a horizontal directional drilling process, according to apossible embodiment of the present disclosure. The display 500 canrepresent a display of a locator device or of the drill rig, and caninclude one or both of a monitor 502 and input buttons 504 a-e used onthat equipment.

In the embodiment shown, the monitor 502 includes a map indicating aplanned route for a drill string. The display includes a route 506extrapolated from a number of captured location points (illustrated bythe “x” notations on the map). The captured location points can becaptured, for example, by placing the locator device at a desiredlocation and pressing an input button (e.g., button 504 a) to signalthat the location is to be captured. An overall route can be mappedusing a further button (e.g., button 504 b). Obstacle information andbore depth can be added to the map as well (e.g., using buttons 504d-e).

Referring now to FIG. 6, the example display 500 is illustrated duringan actual drilling process, for example to track a sonde and associateddrill head once the mapped route is uploaded to a drill rig. In thisillustration, the monitor 502 includes both the mapped route 506 and anactual route 508 travelled by the sonde. The monitor also displays acurrent location 510 of the sonde. As discussed above, the currentlocation 510 can be represented by a circle covering an area of the map,for example representing a confidence level that the sonde is in aparticular location. In such embodiments, a smaller circle wouldrepresent a higher confidence in the sonde's current position. Once thedrilling process is complete, the actual route 508 can represent anas-built map of the bore path. As explained above, the actual route 508,and mapped route 506, can be transmitted back to a HDD data server, suchas server 16, for storage and/or review. Additionally, as the actualroute 508 is tracked, the mapped route 506 can be altered, e.g., due tochanges in conditions or based on changes in the actual route 508, fromthe server 16 or other remote system, such as remote computing system 20of FIG. 1A.

Now referencing both FIGS. 5-6, although a particular layout of buttonsis illustrated, this illustration is for discussion purposes only; it isunderstood that various other arrangements of buttons or displayfeatures could be provided.

Generally using the methods and systems disclosed herein, the locatordevice or drill rig can combine data/information generated by the drillrig and locator device to show an estimated location of a drill head,with information generated by the locating device that comprises both(1) GPS location information related to the location of the locatingdevice and (2) information related to magnetic field strengthmeasurements measured by the locating device that were emitted by asonde associated with the drill head. This allows for simple mapping andtracking of a bore path and boring process, without requiring multiple,repeated electromagnetic field measurements, and allowing a drill headlocation to be directly determined, rather than only tracked relative toa drill rig. Other advantages are provided by the methods and systemsdisclosed herein as well.

As discussed in FIGS. 7-16, some additional techniques may be applied bythe HDD machine and/or the locators to increase the accuracy of thecalculated position based on the received GPS signals. The techniquesdescribed in FIGS. 7-15 may be used in conjunction with any of thesystems and methods described above to determine the position of the HDDmachine, the locators, and/or the drill head. Accordingly, thetechniques described in FIGS. 7-15 may be used to increase the accuracyin tracking a position of the drill head and/or mapping a bore plan.

FIG. 7 illustrates an example drilling system in an example globalpositioning system environment 600. The global positioning systemenvironment 600 includes four or more navigation satellites 650 insteady orbit around the globe.

An HDD machine 702 may be positioned at a location covered by thenetwork 611. One or more locators 704, which are equipped to locate thesonde 708 of the drill string 703, may be deployed in an area around theHDD machine 702.

The HDD machine 702 is configured to receive signals 608 from one ormore satellites 650 by which the HDD machine 702 may calculate itsapproximate position. Each locator 704 also is configured to receivesignals 612 from one or more satellites 650 by which the locator 704 maycalculate its approximate position. In certain implementations, the HDDmachine 702 and the locator 704 each receive signals 608, 612 from foursatellites 650. In certain implementations, the HDD machine 102 and thelocator 704 each receive signals 608, 612 from the same four satellites650.

In some implementations, the global positioning system environment 600is configured to provide differential global positioning. For example,in certain implementations, the global positioning system environment600 also includes one or more reference sites at surveyed locations thatinclude satellite signal receivers 605. Position correction informationcorresponding to the area around each reference site is generated basedon a comparison between the known position and the position obtainedfrom the signal measured by receiver 605.

The receivers 605 are connected to a network 611. In someimplementations, the reference sites are equipped with sufficientprocessing power to calculate their location (i.e., or information fromwhich their location can be calculated) based on the received satellitesignals and to compare the calculated information with their known(e.g., surveyed) position. In such implementations, the receivers 605provide the position correction to the network 611. In otherimplementations, the reference sites provide the measured signals andtheir known location information to the network 611 for subsequentprocessing.

In certain implementations, a computer system 610 (e.g., personalcomputer, server computer, group of networked computers, cloudcomputers, etc.) receives this information from multiple reference sitesand determines the position correction information for an area coveredby the network 611. For example, the position correction information maybe determined for the area around each reference site and the areasbetween two or more reference sites. In some cases, the positioncorrection information can be determined based on information gatheredfrom multiple reference sites. For example, position correctioninformation pertaining to an area between three reference sites may bedetermined based on information obtained at all three reference sites.

The network 611 is configured to disperse the position correctioninformation to one or more satellite receivers (e.g., at the HDD machine702 and/or at the locators 104) within the network 611. In someimplementations, the HDD machine 702 is configured to receive positioncorrection data from the network 611 and to distribute the positioncorrection data to each of the locators 704. For example, the computersystem 610 may send the position correction information to the HDDmachine 702 for dispersal to the locators 704. The HDD machine 702 andthe locators 704 may each apply the position correction information totheir calculations to determine their respective corrected positions.

In some implementations, the HDD machine 702 receives the positioncorrection data over a cellular line 606 and distributes the correctiondata over a radio signal transmission 614. In certain implementations,the HDD machine 702 and the locator 704 communicate over 2-way radiosignals. For example, certain types of HDD machines 702 are configuredto receive the corrected positions of the locators over a radio signaltransmission 616. In other implementations, however, the HDD machine 702may be configured to receive the position correction data over a WIFIsignal, a wired signal, or via some other type of communicationequipment.

In some implementations, the HDD machine 702 and locators 704 mayexchange other types of information. For example, in certainimplementations, the HDD machine 702 may communicate with each locator704 over a two-way radio. In some implementations, the HDD machine 702sends information calculated by the HDD machine 702 to each of thelocators 704. For example, the HDD machine 702 may calculate itscorrected position and send its corrected position to each of thelocators 704. In certain implementations, the HDD machine 702 may obtainmeasurements pertaining to the carrier signal received from thesatellites 650 and may transmit the obtained carrier measurements to thelocators 704 as will be disclosed in more detail herein.

FIG. 8 is a block diagram of an HDD system 700 including the HDD machine702 and the locator device 704 is shown. In the embodiment shown, theHDD machine 702 includes a control system 202 configured to directoperation of the drill string 703 via a mechanical drive unit 204. TheHDD machine 702 also includes a display 706 and I/O interface 708, whichallow an operator to view a current operational status, planned route,and various other parameters of the HDD machine 702. The HDD machine 702also includes a receiver (e.g., a GPS receiver) 212 that is configuredto receive the transmission signals from the satellites 650.

In some implementations, the HDD machine 702 also includes a cellularinterface 214 with which the HDD machine 702 receives the positioncorrection information from the computer system 610. In otherimplementations, the HDD machine 702 includes another type ofcommunications interface to receive the position correction informationfrom the network 611. The HDD machine 702 also includes a two-way radio210′ configured for two-way communication with the locator device 704.The two-way radio 210′ allows position correction data to be dispensedto the locators 104 and to allow data associated with a location of thesonde 708 can be communicated from the locator 704 back to the HDDmachine 702.

The locator device 704 includes a control circuit 220 and a plurality oflocator circuits, shown as GPS locator circuit 222 and EM locatorcircuit 224. The control circuit receives information from the GPSlocator circuit 222 to determine a current location of the locatordevice 704. The control circuit 220 may apply position correction dataobtained from the HDD machine 702 to the determined current location tocompute a corrected position of the locator 704. The locator 704 alsouses the EM locator circuit 224 to receive communications from the sonde108 (e.g., to associate the corrected position of the locator device 704with the location of the sonde 708).

An antenna 226 associated with the EM locator circuit 224 is configuredto pick up electromagnetic signals from the sonde 708 for processing atthe EM locator circuit 224. The EM locator circuit 224 also optionallyreceives information regarding other operational parameters of the sonde708 and associated drill head 706, for example rotational or linearspeed, temperature, or other current operating parameters, such as apitch of bit, clock/roll position of bit, depth of bit, fluid pressureat bit, product tension measured at bit, and vibration at the bit. Otherparameters can be tracked as well. The antenna 226 can be, for example,a simple antennae device for measuring a magnetic field information ofthe signal being transmitted by the sonde 708, as would be useful forgenerating signal strength information, or alternately the antenna 226could be more elaborate to also measure additional characteristics ofthe magnetic field—as would be useful for measuring theshape/orientation of the “flux lines” associated with the sonde 708.

The locator device 704 also includes a complementary two-way radio 228′that communicates with the radio 210′ of the HDD machine 702. Thelocator device 704, therefore, can transmit bore plan information,current operational status information, or other types of information tothe HDD machine 702, such that each machine can track and controloperational features of the drill head 706.

The control circuit 220 performs a number of operations relating to (1)developing a bore plan for a drill rig, and (2) tracking a drill headand associated sonde during operation of the drill rig. The locatordevice 704, in certain implementations, enables display of a number ofparameters relating to operation of the drill head 706 on a display 230,alongside a map of the current location of the locator device 704 andHDD machine 702. The display 230 can be used, for example, to establisha bore plan, or to track the current position of a sonde 708. AssociatedI/O interfaces 232 allow for a keypad or other buttons to be implementedon the locator device 704 as well, for example to assist in mappingvarious features, such as the bore path, bore depth, obstacles, or otherinformation.

FIG. 9 is a block diagram of a computer system 610 forming part of thenetwork 611. The computer system 610 may be implemented on one or morecomputer devices. The computer system 610 includes a controller 620 thatis connected to a cellular interface 624. In some implementations, thecomputer system 610 sends the position correction information to the HDDmachine 702 using the cellular interface 624. In certainimplementations, the computer system 610 also receives information fromthe reference site receivers 605 via the cellular interface 624. Inother implementations, the computer system 610 is otherwise connected tothe reference site receivers 605.

The computer system 610 also includes memory 622 at which positioncorrection data 632 for the network and algorithms 630 for computing theposition correction data 632 are stored. In some implementations, thecontroller 610 receives the position correction data from the referencesite receivers 605 and stores the position correction data in thememory. In other implementations, the controller 610 receives themeasured data and the known position data from the reference sitereceivers 605 and computes the position correction data. In certainimplementations, the controller 610 computes position correction datafor an area in the network that is spaced from one of the reference sitereceivers 605.

FIG. 10 is a flowchart of a method 800 of locating underground drillingequipment using a differential GPS analysis, according to a possibleembodiment of the present disclosure. The method 800 can be, in variousembodiments, performed using an HDD machine, such as the HDD machine 702discussed above. The method 800 starts with the HDD machine 702determining its approximate location (step 802). In someimplementations, the HDD machine 702 receives a signal from one or moresatellites 650 while disposed at a position and calculates its positionbased on the received signal. For example, in certain implementations,the GPS receiver 212 of the HDD machine 702 may receive signals fromfour satellites 650. In other implementations, the GPS receiver 212 mayreceive signals greater or fewer satellites 650.

The HDD machine 702 sends its approximate location to the network 611(step 804). In some implementations, the HDD machine 702 establishes acellular connection to the computer system 610 and sends its approximatelocation to the computer system 610 over the cellular connection. Inother implementations, however, the HDD machine otherwise communicatesits approximate location to the computer system 610. The HDD machine 702receives position correction information (step 806) from the network 611(e.g., from the computer system 610). In some implementations, the HDDmachine 702 receives the position correction information over a cellularsignal. In certain implementations, the HDD machine 702 also receivesfrom the network 611 its own corrected position calculated based on thecorrection information.

The HDD machine 702 distributes the position correction information(step 808) to one or more locators 704. In some implementations, the HDDmachine 702 broadcasts the position correction information to thelocators 704 over a two-way radio, such as radio 210′. In oneembodiment, the HDD machine 702 also sends its own corrected position tothe locators 704. In another embodiment, the HDD machine 702 does notsend its own corrected position to the locators 704. The HDD machine 702receives (step 810) locator information (e.g., a corrected position ofthe locator 704 and attributes of the drill head 706) from the locator704. In some implementations, the HDD machine 702 receives the locatorinformation from the locator 704 over the two-way radio 210′. The HDDmachine 702 determines the location of the drill head 706 (step 812)based on the information received from the locator(s) 704.

FIG. 11 is a flowchart of a method 820 of locating underground drillingequipment using a differential GPS analysis, according to a possibleembodiment of the present disclosure. The method 820 can be, in variousembodiments, performed using a locator device, such as the locator 704discussed above. The method 820 starts with the locator 704 receiving(step 821) a signal from one or more satellites 650 while disposed at aposition. For example, in certain implementations, the GPS receiver 222of the locator 704 may receive signals from four satellites 650. Inother implementations, the GPS receiver 222 may receive signals greateror fewer satellites 650.

The locator 704 also receives position correction information (step 823)from the HDD machine 702 associated with the location. For example, thelocator 704 may receive the position correction information over atwo-way radio 228′. In other implementations, the locator 704 mayotherwise be in communication (e.g., a wired connection, a WiFiconnection, or a cellular connection) with the HDD machine 702. Thelocator 704 computes (step 825) a corrected position for the locator 704using the satellite signals and the position correction informationobtained above.

The locator 704 measures (step 827) attribute information pertaining tothe sonde 708 and/or the drill head 706 while disposed at the sameposition at which the locator 704 received the satellite signals. Forexample, the locator 704 may measure a signal intensity received at theantenna 226. In certain implementations, the signal intensity ismeasured at three of more points, which allows for triangulation of theposition of the sonde 708. The locator 704 sends (step 829) the measuredattribute information to the HDD machine 702 for processing. Optionally,the locator device 704 may compute a position of the drill head 706based on its corrected position and the measured attribute information.Optionally, the locator device 704 may display the position of the drillhead 706 at the display 230.

FIGS. 12-14 are flowcharts providing methods that can be used inlocating underground drilling equipment using carrier phase tracking.The methods of FIGS. 12-14 allow the locators 704 to compute theirrespective corrected locations with increased accuracy. Accordingly, themethods of FIGS. 12-14 may be used in conjunction with, or asalternatives to, the methods of FIGS. 9 and 10. The method 830 of FIG.12 starts with receiving (step 832) signals from one or more satellites650 at the HDD machine 702. For example, in some implementations, theHDD machine 702 receives satellite signals from four differentsatellites 650. The receiver 212 of the HDD machine 702 measures (step834) a phase of the carrier signal over an epoch. The HDD machine 702broadcasts (836) the measured phase to the locators 704.

FIG. 13 is flowchart illustrating one example implementation of step 834of the method of FIG. 12. As part of step 834, the HDD machine 702measures (step 831) the phase of the carrier signal received from afirst satellite 650. The HDD machine 702 also measures (step 833) thephase of the carrier signal received from a second satellite 650.Optionally, the HDD machine 702 also measures (step 835) the phase ofthe carrier signal received from a third satellite 650 and measures(step 837) the phase of the carrier signal received from a fourthsatellite 650. Steps 831-837 are implemented concurrently during thesame epoch.

The method 840 of FIG. 14 is implemented by at least one of the locators704 to obtain a corrected position for the locator 704 relative to theHDD machine 702 with increased accuracy. The method is implemented inconjunction with the HDD machine 702 implementing the method of FIG. 12.The method starts with at least one of the locators 704 applying a firsttriple difference function (step 842) to the carrier phases measured bythe drill and the carrier phases measured by the locator 704 over afirst time pair as will be described in FIG. 15.

The locator 704 applies a second triple difference function (step 844)to the carrier phases measured by the drill and the carrier phasesmeasured by the locator 704 over a second time pair. The locator 704also applies a third triple difference function (step 846) to thecarrier phases measured by the drill and the carrier phases measured bythe locator 704 over a third time pair. The locator 706 determines thecorrected position of the locator 704 (step 848) using the three tripledifference calculations. For example, the locator 704 may determine thecorrected position using the triple difference results, numerical rootfinding, a least squares procedure, and an approximate positiondetermined based on the satellite signal 650. In certainimplementations, correction information obtained from the network 611may be applied to the approximate position to determine a firstcorrected position that may be used in the determining step 848.

In other implementations, the locator 704 may send the results of thethree triple differences to the HDD machine 702 to calculate thecorrected position of the locator 704. In still other implementations,the locator 704 may send the results of the three triple differences tothe HDD machine 702, which forwards the results to the computer system610 for computation of the corrected position of the locator 704. In yetstill other implementations, the locator 704 sends it measured phasesignals to the HDD machine 702, which either calculates the three tripledifferences or forwards the locator's measured phases and the HDDmachines' measured phases to the computer system 610 for processing.

FIG. 15 is a flowchart illustrating a triple difference method 850 thatis suitable for use in implementing each of steps 842, 844, and 846 ofmethod 840. The triple difference method 850 is implemented by one ormore locators 704 in communication with the HDD machine 702. The tripledifference method starts by receiving satellite signals (step 851) atthe locator 704 over an epoch. The locator 704 receives the signals fromthe same satellites as the HDD machine 702. For example, in someimplementations, the receiver 222 of the locator 704 receives signalsfrom four different satellites 650. In other implementations, thelocator 704 receives signals from a greater or lesser number ofsatellites 650.

The locator 704 measures (step 852) the total phase of the signalreceived from each satellite 650 during the epoch. In someimplementations, the locator 704 measures the total phase of the carriersignal from each satellite. The locator 704 also receives (step 853) thetotal phase of each satellite signal measured by the HDD machine 702over the same epoch. The locator 704 computes a double difference (step854) of the phases.

For example, in certain implementations, the locator 704 analyzes themeasured phases and finds a first difference between the carrier phaseof a first satellite 650 as measured by the locator 704 and the carrierphase of the first satellite 650 as measured by the HDD machine 702during the epoch. The locator 704 also finds a second difference betweenthe carrier phase of a second satellite as measured by the locator 704and the carrier phase of the second satellite as measured by the HDDmachine 702 during the same epoch.

The locator 704 determines (step 855) whether another double differenceof the satellite signals has already been computer for a different timeperiod. For example, the locator 704 may access the memory 234 of thelocator 704 to determine whether such a double difference result hasbeen stored. If no other double difference results has been computed,then the locator 704 stores (step 856) the computed double differenceresult in memory 234. The triple difference method 850 then cycles backto the receiving step 842 and begins again.

If another double difference has already been computed for the satellitesignals obtained over a second epoch, then the locator 704 comparescomputes a triple difference (step 857) of a time pair by comparing thedouble difference pertaining to signals obtained over the first epochwith the double difference pertaining to signals obtained over thesecond epoch.

As noted in the method 840 of FIG. 14, a triple difference is found forat least three different time pairs. In other words, the tripledifference is found between the phases measured by the HDD machine 702and the phases measured by the locator 704 from the same satellitesignals received over the same six time periods. Finding the tripledifference of these measured phases ameliorates the effects of clockbias errors and integer ambiguity when measuring the satellite signals.

FIG. 16 is a flowchart illustrating a method 860 by which a GPS systemcan be used to guide (i.e., direct) an operator to the approximatelocation of the drill head 706. The method 860 starts with determiningan approximate position of a drill head 706 (step 861). In someimplementations, the approximate position of the drill head 706 isdetermined by determining a position of the HDD machine 702 anddetermining attributes of a drill string 703 extending from the HDDmachine 702. For example, the position of the HDD machine 702 may bedetermined using a GPS receiver 212 on the HDD machine 702. Theattributes of the drill string 703 include the direction and speed oftravel of the drill head 706 and/or the number of drill rods used in thedrill string 703.

One or more locators 704 are positioned (step 862) at the approximateposition of the drill head 706. A geographic position of each locator704 is determined (step 863). For example, the locator 704 may use theGPS receiver 222 to determine its geographic position. In someimplementations, the GPS data obtained by the locators 704 may beenhanced, e.g., using differential GPS, carrier phase tracking, and/orrelative kinematic positioning. Each locator 704 also measures (step864) a signal strength/intensity from the sonde 708 at the drill head706. For example, the locator 704 uses the EM antenna 226 and locatorcircuit 224 to measure the signal from the sonde 708. Accordingly, eachsignal strength measurement is associated with a geographic position.

EM signal strength can be directly related to the proximity of thereading location (i.e., the geographic position of the locator 704) andthe sonde location (i.e., the geographic position of the drill head706). In particular, for each geographic position of the locator 704,the sonde 708 is located along a circumference of a sphere around thegeographic position. The radius of the sphere corresponds to thestrength/intensity of the signal received from the sonde 708.

Steps 862-864 of the method 860 are repeated until readings have beenobtained for at least three geographic positions (step 865). In certainimplementations, steps 862-864 are repeated for more than threegeographic positions. For example, steps 862-864 may be repeated untilat least three geographic positions are associated with measurementsabove a predetermined threshold. The at least three geographic positionsare then triangulated (step 866) to determine the sonde location (and,hence, the drill head 706). In some implementations, the triangulationanalysis also includes a calculated circumference of a sphere centeredon the geographic position of the HDD machine 702 and having a radiusequal to a length of the drill string 703.

The operator is guided (step 867) to the geographic position of thedrill head 706. For example, the locator 704 may display a map of thearea with a marking showing the geographic position of the sonde 708. Incertain implementations, the map also may include a marker indicatingthe geographic position of the HDD machine 702 and/or another landmark.In other implementations, the map may be displayed at the HDD machine702.

Referring now to FIGS. 17-18, a locating technique employing GPS-basedtechnologies is shown, intending to account for theuncertainty/variation issues discussed above in connection with FIGS.5-6, and in which In particular, FIG. 17 illustrates an example locationtechnique is displayed, useable in connection with the methods andsystems disclosed herein, in which a GPS-based locating system isemployed. In the embodiment shown, a bore path sequence 900 isillustrated, accounting for uncertainty or variance introduced byGPS-based location. In various embodiments, GPS-based systems may havean uncertainty as to exact location, with a variance of between actualand sensed location of approximately 3 feet. This is represented in thebore path sequence by a first bore path location 910 having a startingpoint 902, estimated current endpoint 912 of a drill string 914, with acircle 916 representing possible variance in actual location as comparedto detected location. As such, bore path location 910 generallycorresponds to a current location of a drill head (e.g., a sonde orrelated boring tool) as detected by a locator, such as might bedisplayed on a display such as is shown in FIGS. 5-6. It is noted thatusing the various techniques discussed above in connection with FIGS.7-16 relating to triangulation, in some cases variance may be lower than3 feet; however, in other cases where it is difficult to obtain anaccurate GPS signal, accuracy may be substantially lower. In eitherevent, accuracy can be improved due to use of a known drill stringlength, which allows narrowing the possible locations of the drill headto those illustrated in region 918, which are a part of the circle 916.

As drilling proceeds and the drill head moves underground, additionallocations can be detected, and the length of the drill stringcontinually monitored. As seen in the second bore path location 920 ofthe sequence 900, it is noted that a subsequent drill head location canbe determined for the drill string 914, by locating a second estimatedcurrent endpoint 912′, and with a second circle 916′ representing thevariance in location at this second GPS-captured location. Based on thesecond circle 916′ and a known second length of the drill string 914, asecond narrowed region 922 can be established. It is noted that, basedon this second narrowed region 922, the first narrowed region 918 can benarrowed to region 918′, due to a limit on the possible paths betweenthe various possible locations known at the time of the first bore pathlocation capture 910 and the current bore path location 920, as well asthe known length of the drill string 914 at the second bore pathlocation 920.

A third bore path location 930 illustrates a further refinement of thebore path due to a third location capture operation using a GPS unit ona locator, at a third estimated endpoint 912″. In this case, the thirdbore path location results in a third circle 916″ representinguncertainty at this location as narrowed to a region 932 based on aknown length of the drill string. Based on this information, a furthernarrowed region 918″ can be determined at the first location 910 and anarrowed region 922′ at the second location. As such, as a boringoperation proceeds along a planned boring path, a known drill stringlength and estimated current location of a drill head can be used tofurther refine earlier locations along the boring path. As such, evenusing periodic estimated locations of a drill head based on GPSvariances, an accurate drill string record can be built during theboring process. This “as built” boring path, as determined during theboring process, can be displayed on a display of a drill rig as in FIGS.5-6, and can be periodically updated based on subsequent locationdeterminations. In some embodiments, these periodic path locations canbe captured at the end of each drill string segment, or other regulardistance. It is noted that in some circumstances, accuracy as to thelocation of a drill string may be determined only after the drill headhas already passed a particular location by a predetermined distance(e.g., 2-3 drill segments).

In some additional embodiments, it is noted that in addition to currentand past locations of a drill head, depth information could be capturedas well, and determined relative to a current elevation of the locatoras determined by a GPS device.

Referring now to FIG. 18, a generalized process 1000 performed using thelocator device is described for refining location data relative to adrill string during a boring operation. The process can be used, forexample, to accomplish the location refinement discussed in connectionwith FIG. 17, and can be performed, in various embodiments, in aGPS-enabled locator device, or on a drill rig associated with such alocator, as described above. In the embodiment shown, the process 1000includes determining an initial position of a drill rig (i.e., astarting location of a boring process) (step 1002). The process furtherincludes performing an underground horizontal directional drillingoperation, i.e., a boring operation, for a known distance (step 1004).The process next includes capturing a GPS location reading at anabove-ground position above the drill head, for example using a locatordevice with integrated GPS (step 1006). This results in a capturedcurrent location, with a generally circular variance (e.g., circles 916,916′, 916′″ of FIGS. 17). A total drill string length is determined(step 1008), and the current location of the drill head is narrowedbased on that known drill string length, to arrive at a narrowedvariation of current locations of a drill head (step 1010). Any priorlocations that have been captured are then updated to narrow thosepossible locations based on the current variance of locations of thedrill head (e.g., resulting in narrowed locations 918′, 918″, or 922′ ofFIG. 17). Each of the calculated locations are then recorded, and theboring process continues at step 1004 to continue boring anotherdistance (e.g., another drill string segment).

Referring to FIGS. 17-18, it is noted that when drilling is completed,an end position of the drill string may be known, since the drill headwould emerge at a far end of a bore. As such, additional certainty canbe derived from that location, and interim locations captured during theboring process can be further updated, leading to an accurate “as built”bore path using inherently inaccurate locating technologies. Asdiscussed below, such an “as built” bore path can then be stored forreview either by the rig or in a computing system remote from the jobsite.

Referring now to FIGS. 19-20, additional features are discussedregarding operation of an overall network including one or more HDDmachines, such as machines 14, 102, 702 described above. In general,FIGS. 19-20 describe management and tracking of data captured at an HDDmachine, including operational parameters of the drill rig itself, aswell as location data regarding planned, current and historicallocations of a sonde associated with a drill head.

As illustrated in FIG. 19, a HDD machine 1102 is communicativelyconnected to an HDD data server 1104 via a network 1106. The HDD machinecan be any of a variety of machines, such as machines 14, 102, 702described above. The HDD data server 1104 can be any of a variety oftypes of computing systems or computing resources capable of storage andretrieval of data associated with horizontal directional drilling. Invarious alternative embodiments, the HDD data server 1104 is either aserver resource or a cloud-based, distributed computing resourceavailable to be communicatively connected to the HDD machine 1102. Thenetwork 1106 can be any of a variety of data networks capable ofproviding real-time or near real-time data exchanges between the HDDdata server 1104 and the HDD machine 1102, such that data is accessibleby a remote computing system (e.g., system 20 of FIG. 1A).

As illustrated in FIG. 17, the HDD data server 1104 can exchange avariety of types of data with the HDD machine 1102, as well as othercomputing systems authorized to access such data. In the exampleembodiment shown, the HDD data server 1104 includes a database 1108 thatis configured to store various types of information relevant to a jobsite. In the embodiment shown, the database 1108 includes bore plan data1110, boring logs 1112, job data 1114, site data 1116, rig telematicsdata 1118, maintenance data 1120, and reports 1122; however, inalternative embodiments, other types of data could be included as well.

In the embodiment shown, bore plan data 1110 refers to data generated inadvance of a boring operation, relating to a planned route for a boringtool to travel, as explained above. Example types of bore plan data arediscussed, for example, in U.S. Pat. No. 6,749,029, the disclosure ofwhich is hereby incorporated by reference in its entirety. Similarly,boring logs 1112 refer to data recorded regarding the actual path of theboring tool during a boring operation. Boring logs 1112 generally caninclude one or more types of location data, such as GPS coordinates orrelative location data, as well as timestamps and optionally depthinformation, allowing a user to map a three-dimensional route of anactual bore that either is in the process of being created or haspreviously been created. Through use of the bore plan data 1110 andboring logs 1112, a remote computing system can also display remotely amapped route 506 vs. an actual route 508, as was otherwise illustratedabove as being displayed at an HDD machine and/or locator.

In general job data 1114 and site data 1116 correspond to data thatdescribe a particular boring operation to be performed. Job data caninclude, for example, data relating to a particular job to be performed,such as specifications for the job (e.g., bore size, length, cost,timing, etc.), personnel associated with the job (e.g., the HDD machineand/or locator operator(s), project manager, or other individuals), andthe specific equipment assigned to carry out the job. The specificequipment data can include the model of the HDD machine used, as well ascharacteristics of a locator (e.g., type of locating technology) andother components used at the job site (e.g., characteristics of thedrill string, such as its bend/steering characteristics, orcharacteristics of other add-on modules useable with the HDD machine).Site data 1116 can include a variety of types of information describingthe site at which the HDD operation takes place. For example, site data1116 can include, among other elements, site boundary information,existing utility information, topographical information, groundcomposition information (e.g., soil conditions, obstacles, etc.), watertable information or other analogous information. Job data 1114 and sitedata 1116 can be used to define a scope of and parameters surrounding aparticular project, and can be used to manage timing of and expectedscheduling of various HDD jobs to be performed with various pieces ofequipment owned or controlled by the entity managing such data.

Rig telematics data 1118 refers to information tracked by and intendedto be programmed into an HDD machine to guide and/or track its operationduring an HDD operation. Example rig telematics data 1118 can includeoperational programming for the HDD machine as well as operational dataof the HDD machine during a boring operation, for example, datacollected at the HDD machine from operational subsystems of the HDDmachine, as well as various components connected thereto. This caninclude, for example, data and dashboards relating to operation of themachine, such as engine speed, attachment speed, attachment pressure,steering position, track direction and speed, boom depth, time of day,auto-plunge status, fuel level status and fuel consumption, hydraulicoil temperature difference, track pressure, engine hours, attachmentcharge pressures, accumulator pre-charge pressures, engine oil pressure,engine coolant temperature, system voltage, or hydraulic oiltemperature. Example telematics data is described in U.S. patentapplication Ser. No. 11/853,396, filed Sep. 11, 2007, the disclosure ofwhich is hereby incorporated by reference in its entirety.

Maintenance data 1120 refers to data relating to servicing the variousHDD machines in use by a particular entity. For example, maintenancedata 1120 can include service records, warranty information, or otherdata associated with the relationship between an owner of the HDDmachine and its dealer and/or manufacturer.

Reports 1122 can include any of a variety of post-job data compilationsuseable to assess performance of the entity performing the HDD job.Reports can include, for example, assessments of an overall cost tocomplete an HDD job (a particular job or averaged across jobs), or costof ownership of an HDD machine (either a particular machine or onaverage across all machines associated with an entity). In someembodiments, reports 1122 can be generated either at the HDD machine orat a back-end database (e.g., HDD data server 1104), and can begenerated based on collected telematics information, locationinformation, or other information describing the machine or job. Forexample, drill rig pressures (e.g. oil pressure) and drilling resistancemeasures could be correlated with a particular sonde location, with thecorrelation indicating that the HDD machine was encountering a type ofrock or obstacle that is difficult to bore through. Using the variousreports, it is possible to further develop one or more report-basedmodules at the system 1100 capable of assisting with forecasting totalcosts and therefore advisable bid amounts for particular jobs. In someexample embodiments, reports can be customized and generated at the HDDdata server 1104, and exported to one or more different known softwareformats (e.g., a spreadsheet or web reporting format).

Referring now to FIG. 20, an example flowchart of a method 1200 foroperating a horizontal directional drilling system is disclosed, inwhich an HDD machine 1102 is communicatively connected to remote datamanagement components as described above. The method 1200 generallycorresponds to operations that are capable of being performed remotelyfrom the job site based on communicated data at an HDD data server 1104;however, it is recognized that one or more of the operations discussedherein could instead be performed locally at the job site.

As illustrated, the method 1000 generally includes communicativelyconnecting one or more drill rigs to a data collection system, such asthe HDD data server 1104 of FIG. 19 (step 1202). This can include, forexample, placement of the HDD machines at corresponding job sites andestablishing data connectivity between the HDD machines and the HDD dataserver.

An operator can then cause the HDD data server 1104, either directly orvia a remote computing system, to transmit data to the HDD machine 1102in preparation for the boring operation to be performed at the job sitewhere that HDD machine is located (step 1204). The data transmitted tothe HDD machine 1102 prior to operation can include a variety oftelematics dashboards or other features useable by the HDD machine toaccomplish the drilling process. In various embodiments, the telematicsinformation can be transmitted to the HDD machine 1102 in single packageor in a plurality of selectable, self-contained packages. In embodimentswhere the telematics information is transmitted using a plurality ofself-contained packages, it is possible that only a subset of thosepackages may be downloaded to the HDD machine 1102, as needed foroperation. The data transmitted to the HDD machine 1102 prior tooperation can also include various types of operational data useable bythe drill rig. This can include, for example, site data and job datadeveloped for the site can be transmitted to the HDD machine. It canalso include a definition of specific equipment and/or processes to beused during the boring process associated with the job.

Additionally, before operation of the HDD machine 1102 in a boringprocess, a computing system may transmit bore plan and/or map data tothe HDD machine (step 1206). The map data can include one or moretopographical maps (two- or three-dimensional) of the area in whichdrilling is to occur, as well as data describing obstacles present inthe area (e.g., specific rock, buildings, or underground utilities to beavoided). The bore plan data can include a proposed or planned route forboring to take place, and can be configured to be overlaid with the mapdata at the HDD machine (as well as at a remote system). As such, it ispreferable that a common set of coordinates (e.g., GPS or otherarrangement) or relative locations from a common point is used.

During operation of the HDD machine (i.e., during the boring process),the HDD data server 1104 is configured to receive HDD job data (step1208). This includes receiving, in real-time or near real-time, updatesregarding some or all of the operational parameters of the HDD machine,as well as updates regarding location and operation of the boring toolincluding the sonde. In varying embodiments, the HDD data server 1104can alternatively receive a portion of the information captured at theHDD machine in realtime and a portion after completion of a job.

It is noted that, during operation of the HDD machine, in someembodiments it is possible to transmit additional or alternative boreplan or map data to the HDD machine 1102 from the HDD data server 1104(e.g., via step 1206). For example, based on observed telemetryinformation received from the HDD machine 1102, it may be observed by aremote user of the overall system that a portion of the bore plan mayneed to be altered, for example due to a variance in the bore from anexpected value, or based on other data received from the HDD machine instep 1208. In such embodiments, a map of the job site, as well as boththe bore plan and actual bore location can be displayed to a user of theremote computing system via an analogous interface to that provided onthe HDD machine, such as that illustrated in FIGS. 5-6.

Upon completion of the job, an HDD data server 1106 can generate one ormore job reports relating to one or more completed HDD jobs. Indiffering embodiments, the HDD data server 1106 can either automaticallygenerate such reports, or can be instructed to do so by a user. Thereports can include, for example: a comparison between an actual boringpath (e.g., an “as-built” bore) and a planned bore path; service ormaintenance reports required of an HDD machine either during or after ajob; alerts that have arisen during a job, such as dangerous pressure ortension levels; and cost of ownership/cost of job/cost of operationmetrics. Other types of reports are possible as well, and custom reportscould be defined by a user of the overall system 1100.

Referring generally to FIGS. 19-20, it is noted that although thegeneral method 1200 is discussed with respect to a single job site andHDD machine 1102, it is recognized that the HDD data server 1104 couldin many embodiments concurrently support management and storage of datarelating to a plurality of different HDD machines 1102 at geographicallydispersed job sites. Furthermore, it is noted that a single individualat a remote site may be able to, via the HDD data server 1104, monitorand provide guidance (e.g., bore plans or other data) to various HDD jobsites concurrently, thereby allowing for real-time supervision andintervention into HDD operations as needed. As such, due to the multiplepossible HDD machines that can access or provide data to/from the HDDdata server, in some embodiments the system 1100 is arranged such thatthe HDD machine 1102 or other remote computing systems initiate dataexchanges with the HDD data server 1104 as required by that remotesystem.

Referring now to FIGS. 1-20 generally, it is noted that in someembodiments the HDD machines described herein can be interfaced with acomputing system (e.g., a server or remote system) capable of viewingand/or interacting with data obtained from or developed for use in anHDD environment. It is noted that, although the terms “server” and“remote computing system” are used in the present disclosure, it isrecognized that Additionally, it is noted that the methods disclosedherein may be performed at one or more locations within an overallhorizontal directional drilling environment, executed on one or morecomputing systems disclosed herein, or embodied as program instructionson one or more communication media, computer-readable media, or computerstorage media.

In accordance with the present disclosure, the term computer readablemedia as used herein may include computer storage media andcommunication media. As used in this document, a computer storage mediumis a device or article of manufacture that stores data and/orcomputer-executable instructions. Computer storage media may includevolatile and nonvolatile, removable and non-removable devices orarticles of manufacture implemented in any method or technology forstorage of information, such as computer readable instructions, datastructures, program modules, or other data. By way of example, and notlimitation, computer storage media may include dynamic random accessmemory (DRAM), double data rate synchronous dynamic random access memory(DDR SDRAM), reduced latency DRAM, DDR2 SDRAM, DDR3 SDRAM, DDR4 SDRAM,solid state memory, read-only memory (ROM), electrically-erasableprogrammable ROM, optical discs (e.g., CD-ROMs, DVDs, etc.), magneticdisks (e.g., hard disks, floppy disks, etc.), magnetic tapes, and othertypes of devices and/or articles of manufacture that store data. Inembodiments of the present disclosure, computer storage media excludestransitory signals.

Communication media may be embodied by computer readable instructions,data structures, program modules, or other data in a modulated datasignal, such as a carrier wave or other transport mechanism, andincludes any information delivery media. The term “modulated datasignal” may describe a signal that has one or more characteristics setor changed in such a manner as to encode information in the signal. Byway of example, and not limitation, communication media may includewired media such as a wired network or direct-wired connection, andwireless media such as acoustic, radio frequency (RF), infrared, andother wireless media.

The above specification, examples and data provide a completedescription of the manufacture and use of the composition of theinvention. Since many embodiments of the invention can be made withoutdeparting from the spirit and scope of the invention, the inventionresides in the claims hereinafter appended.

1. (canceled)
 2. A locator system for determining a location of a drillhead, comprising: a locating device including a global positioningsystem (GPS) configured to determine a location of a sonde associatedwith a drill head; a controller configured to: receive a first locationof the sonde as determined by the locating device; receive a secondlocation of the sonde subsequent to the first location as determined bythe locating device; refine the second location based on knowninformation associated with the drill head; and refine the firstlocation based on the refined second location and the known informationassociated with the drill head.
 3. The locator system of claim 2,wherein the controller is further configured to refine the firstlocation based on the known information associated with the drill head.4. The locator system of claim 2, wherein the known informationassociated with the drill head includes a known length of a drill stringassociated with the drill head.
 5. The locator system of claim 2,wherein the controller is further configured to receive a third locationof the sonde subsequent to the second location as determined by thelocating device; refine the third location based on the knowninformation associated with the drill head; further refine the secondlocation based on the refined third location and the known informationassociated with the drill head; and further refine the first locationbased on the refined second and third locations and the knowninformation associated with the drill head.
 6. The locator system ofclaim 2, further comprising a memory accessible by the controller,wherein the controller is further configured to record the firstlocation, the second location, the refined second location, and therefined first location in the memory.
 7. The locator system of claim 2,wherein the controller is further configured to receive a bore depthassociated with the first location data.
 8. The locator system of claim2, wherein the controller is further configured to receive dataassociated with obstacles present in a vicinity of the locator device.9. The locator system of claim 2, further comprising a second locatingdevice configured to sense an electromagnetic field emanating from thesonde, wherein first location received by the controller is determinedby the first and second locating devices.
 10. A method of determining alocation of a drill head, comprising: determining a first location of asonde associated with a drill head by a global positioning system (GPS)locating device; determining a second location of the sonde subsequentto the first location by the GPS locating device; refining the secondlocation based on known information associated with the drill head; andrefining the first location based on the refined second location and theknown information associated with the drill head.
 11. The method ofclaim 10, further comprising refining the first location based on theknown information associated with the drill head.
 12. The method ofclaim 10, wherein the known information associated with the drill headincludes a known length of a drill string associated with the drillhead.
 13. The method of claim 10, further comprising: determining athird location of the sonde subsequent to the second location by the GPSlocating device; refining the third location based on the knowninformation associated with the drill head; further refining the secondlocation based on the refined third location and the known informationassociated with the drill head; and further refining the first locationbased on the refined second and third locations and the knowninformation associated with the drill head.
 14. The method of claim 10,further comprising recording the first location, the second location,the refined second location, and the refined first location.
 15. Themethod of claim 10, further comprising determining a bore depthassociated with the first location data.